Magnetically controlled fiber Bragg grating shifts wavelength 15 nm

To create wavelength-programmable fiber Bragg gratings for dense-wavelength-division multiplexing (DWDM), researchers at Lucent Technologies--Bell Labs (Murray Hill, NJ) have devised a method of applying latchable magnetic force. This approach differs from previous schemes based on thermal tuning, use of piezoelectric transducers, and magnetostriction by providing latching ability on the wavelength shift without the need for sustained power, a large tunability range, and high tuning speed. The d

Magnetically controlled fiber Bragg grating shifts wavelength 15 nm

To create wavelength-programmable fiber Bragg gratings for dense-wavelength-division multiplexing (DWDM), researchers at Lucent Technologies--Bell Labs (Murray Hill, NJ) have devised a method of applying latchable magnetic force. This approach differs from previous schemes based on thermal tuning, use of piezoelectric transducers, and magnetostriction by providing latching ability on the wavelength shift without the need for sustained power, a large tunability range, and high tuning speed. The device contains two iron-based programmable magnets 5.6 cm long and 0.26 cm in diameter, latchable because the programmable magnets retain a remnant magnetization that can be reprogrammed. One magnet is fixed; the other is mobile. The fiber containing the grating is epoxy-bonded to the magnets at spots just outside the grating. Changing the magnetization of the magnets with a solenoid alters the grating wavelength. Initial experiments shifted the wavelength starting at 1549.7 nm by 0.8,1.6, 2.4, 3.2, and 4.0 nm. Increasing the magnet size and field strength produced shifts of approximately 15.7 nm, corresponding to about a 39-channel shift in a 50-GH¥DWDM system. Contact: Sung Ho Jin at jin@lucent.com.

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